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• Oracle Solaris 11 ZFS Lab for Openworld 2012

  - by user12626122

  Preface This is the content from the Oracle Openworld 2012 ZFS lab. It was well attended - the feedback was that it was a little short - thats probably because in writing it I bacame very time-concious after the ASM/ACFS on Solaris extravaganza I ran last year which was almost too long for mortal man to finish in the 1 hour session. Enjoy. Table of Contents Exercise Z.1: ZFS Pools Exercise Z.2: ZFS File Systems Exercise Z.3: ZFS Compression Exercise Z.4: ZFS Deduplication Exercise Z.5: ZFS Encryption Exercise Z.6: Solaris 11 Shadow Migration Introduction This set of exercises is designed to briefly demonstrate new features in Solaris 11 ZFS file system: Deduplication, Encryption and Shadow Migration. Also included is the creation of zpools and zfs file systems - the basic building blocks of the technology, and also Compression which is the compliment of Deduplication. The exercises are just introductions - you are referred to the ZFS Adminstration Manual for further information. From Solaris 11 onward the online manual pages consist of zpool(1M) and zfs(1M) with further feature-specific information in zfs_allow(1M), zfs_encrypt(1M) and zfs_share(1M). The lab is easily carried out in a VirtualBox running Solaris 11 with 6 virtual 3 Gb disks to play with. Exercise Z.1: ZFS Pools Task: You have several disks to use for your new file system. Create a new zpool and a file system within it. Lab: You will check the status of existing zpools, create your own pool and expand it. Your Solaris 11 installation already has a root ZFS pool. It contains the root file system. Check this: root@solaris:~# zpool list NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT rpool 15.9G 6.62G 9.25G 41% 1.00x ONLINE - root@solaris:~# zpool status pool: rpool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM rpool ONLINE 0 0 0 c3t0d0s0 ONLINE 0 0 0 errors: No known data errors Note the disk device the root pool is on - c3t0d0s0 Now you will create your own ZFS pool. First you will check what disks are available: root@solaris:~# echo | format Searching for disks...done AVAILABLE DISK SELECTIONS: 0. c3t0d0 <ATA-VBOX HARDDISK-1.0 cyl 2085 alt 2 hd 255 sec 63> /pci@0,0/pci8086,2829@d/disk@0,0 1. c3t2d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@2,0 2. c3t3d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@3,0 3. c3t4d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@4,0 4. c3t5d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@5,0 5. c3t6d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@6,0 6. c3t7d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@7,0 Specify disk (enter its number): Specify disk (enter its number): The root disk is numbered 0. The others are free for use. Try creating a simple pool and observe the error message: root@solaris:~# zpool create mypool c3t2d0 c3t3d0 'mypool' successfully created, but with no redundancy; failure of one device will cause loss of the pool So destroy that pool and create a mirrored pool instead: root@solaris:~# zpool destroy mypool root@solaris:~# zpool create mypool mirror c3t2d0 c3t3d0 root@solaris:~# zpool status mypool pool: mypool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM mypool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c3t2d0 ONLINE 0 0 0 c3t3d0 ONLINE 0 0 0 errors: No known data errors Back to topExercise Z.2: ZFS File Systems Task: You have to create file systems for later exercises. You can see that when a pool is created, a file system of the same name is created: root@solaris:~# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 86.5K 2.94G 31K /mypool Create your filesystems and mountpoints as follows: root@solaris:~# zfs create -o mountpoint=/data1 mypool/mydata1 The -o option sets the mount point and automatically creates the necessary directory. root@solaris:~# zfs list mypool/mydata1 NAME USED AVAIL REFER MOUNTPOINT mypool/mydata1 31K 2.94G 31K /data1 Back to top Exercise Z.3: ZFS Compression Task:Try out different forms of compression available in ZFS Lab:Create 2nd filesystem with compression, fill both file systems with the same data, observe results You can see from the zfs(1) manual page that there are several types of compression available to you, set with the property=value syntax: compression=on | off | lzjb | gzip | gzip-N | zle Controls the compression algorithm used for this dataset. The lzjb compression algorithm is optimized for performance while providing decent data compression. Setting compression to on uses the lzjb compression algorithm. The gzip compression algorithm uses the same compression as the gzip(1) command. You can specify the gzip level by using the value gzip-N where N is an integer from 1 (fastest) to 9 (best compression ratio). Currently, gzip is equivalent to gzip-6 (which is also the default for gzip(1)). Create a second filesystem with compression turned on. Note how you set and get your values separately: root@solaris:~# zfs create -o mountpoint=/data2 mypool/mydata2 root@solaris:~# zfs set compression=gzip-9 mypool/mydata2 root@solaris:~# zfs get compression mypool/mydata1 NAME PROPERTY VALUE SOURCE mypool/mydata1 compression off default root@solaris:~# zfs get compression mypool/mydata2 NAME PROPERTY VALUE SOURCE mypool/mydata2 compression gzip-9 local Now you can copy the contents of /usr/lib into both your normal and compressing filesystem and observe the results. Don't forget the dot or period (".") in the find(1) command below: root@solaris:~# cd /usr/lib root@solaris:/usr/lib# find . -print | cpio -pdv /data1 root@solaris:/usr/lib# find . -print | cpio -pdv /data2 The copy into the compressing file system takes longer - as it has to perform the compression but the results show the effect: root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.35G 1.59G 31K /mypool mypool/mydata1 1.01G 1.59G 1.01G /data1 mypool/mydata2 341M 1.59G 341M /data2 Note that the available space in the pool is shared amongst the file systems. This behavior can be modified using quotas and reservations which are not covered in this lab but are covered extensively in the ZFS Administrators Guide. Back to top Exercise Z.4: ZFS Deduplication The deduplication property is used to remove redundant data from a ZFS file system. With the property enabled duplicate data blocks are removed synchronously. The result is that only unique data is stored and common componenents are shared. Task:See how to implement deduplication and its effects Lab: You will create a ZFS file system with deduplication turned on and see if it reduces the amount of physical storage needed when we again fill it with a copy of /usr/lib. root@solaris:/usr/lib# zfs destroy mypool/mydata2 root@solaris:/usr/lib# zfs set dedup=on mypool/mydata1 root@solaris:/usr/lib# rm -rf /data1/* root@solaris:/usr/lib# mkdir /data1/2nd-copy root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.02M 2.94G 31K /mypool mypool/mydata1 43K 2.94G 43K /data1 root@solaris:/usr/lib# find . -print | cpio -pd /data1 2142768 blocks root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.02G 1.99G 31K /mypool mypool/mydata1 1.01G 1.99G 1.01G /data1 root@solaris:/usr/lib# find . -print | cpio -pd /data1/2nd-copy 2142768 blocks root@solaris:/usr/lib#zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.99G 1.96G 31K /mypool mypool/mydata1 1.98G 1.96G 1.98G /data1 You could go on creating copies for quite a while...but you get the idea. Note that deduplication and compression can be combined: the compression acts on metadata. Deduplication works across file systems in a pool and there is a zpool-wide property dedupratio: root@solaris:/usr/lib# zpool get dedupratio mypool NAME PROPERTY VALUE SOURCE mypool dedupratio 4.30x - Deduplication can also be checked using "zpool list": root@solaris:/usr/lib# zpool list NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT mypool 2.98G 1001M 2.01G 32% 4.30x ONLINE - rpool 15.9G 6.66G 9.21G 41% 1.00x ONLINE - Before moving on to the next topic, destroy that dataset and free up some space: root@solaris:~# zfs destroy mypool/mydata1 Back to top Exercise Z.5: ZFS Encryption Task: Encrypt sensitive data. Lab: Explore basic ZFS encryption. This lab only covers the basics of ZFS Encryption. In particular it does not cover various aspects of key management. Please see the ZFS Adminastrion Manual and the zfs_encrypt(1M) manual page for more detail on this functionality. Back to top root@solaris:~# zfs create -o encryption=on mypool/data2 Enter passphrase for 'mypool/data2': ******** Enter again: ******** root@solaris:~# Creation of a descendent dataset shows that encryption is inherited from the parent: root@solaris:~# zfs create mypool/data2/data3 root@solaris:~# zfs get -r encryption,keysource,keystatus,checksum mypool/data2 NAME PROPERTY VALUE SOURCE mypool/data2 encryption on local mypool/data2 keysource passphrase,prompt local mypool/data2 keystatus available - mypool/data2 checksum sha256-mac local mypool/data2/data3 encryption on inherited from mypool/data2 mypool/data2/data3 keysource passphrase,prompt inherited from mypool/data2 mypool/data2/data3 keystatus available - mypool/data2/data3 checksum sha256-mac inherited from mypool/data2 You will find the online manual page zfs_encrypt(1M) contains examples. In particular, if time permits during this lab session you may wish to explore the changing of a key using "zfs key -c mypool/data2". Exercise Z.6: Shadow Migration Shadow Migration allows you to migrate data from an old file system to a new file system while simultaneously allowing access and modification to the new file system during the process. You can use Shadow Migration to migrate a local or remote UFS or ZFS file system to a local file system. Task: You wish to migrate data from one file system (UFS, ZFS, VxFS) to ZFS while mainaining access to it. Lab: Create the infrastructure for shadow migration and transfer one file system into another. First create the file system you want to migrate root@solaris:~# zpool create oldstuff c3t4d0 root@solaris:~# zfs create oldstuff/forgotten Then populate it with some files: root@solaris:~# cd /var/adm root@solaris:/var/adm# find . -print | cpio -pdv /oldstuff/forgotten You need the shadow-migration package installed: root@solaris:~# pkg install shadow-migration Packages to install: 1 Create boot environment: No Create backup boot environment: No Services to change: 1 DOWNLOAD PKGS FILES XFER (MB) Completed 1/1 14/14 0.2/0.2 PHASE ACTIONS Install Phase 39/39 PHASE ITEMS Package State Update Phase 1/1 Image State Update Phase 2/2 You then enable the shadowd service: root@solaris:~# svcadm enable shadowd root@solaris:~# svcs shadowd STATE STIME FMRI online 7:16:09 svc:/system/filesystem/shadowd:default Set the filesystem to be migrated to read-only root@solaris:~# zfs set readonly=on oldstuff/forgotten Create a new zfs file system with the shadow property set to the file system to be migrated: root@solaris:~# zfs create -o shadow=file:///oldstuff/forgotten mypool/remembered Use the shadowstat(1M) command to see the progress of the migration: root@solaris:~# shadowstat EST BYTES BYTES ELAPSED DATASET XFRD LEFT ERRORS TIME mypool/remembered 92.5M - - 00:00:59 mypool/remembered 99.1M 302M - 00:01:09 mypool/remembered 109M 260M - 00:01:19 mypool/remembered 133M 304M - 00:01:29 mypool/remembered 149M 339M - 00:01:39 mypool/remembered 156M 86.4M - 00:01:49 mypool/remembered 156M 8E 29 (completed) Note that if you had created /mypool/remembered as encrypted, this would be the preferred method of encrypting existing data. Similarly for compressing or deduplicating existing data. The procedure for migrating a file system over NFS is similar - see the ZFS Administration manual. That concludes this lab session.

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• Partnering with your Applications – The Oracle AppAdvantage Story

  - by JuergenKress

  So, what is Oracle AppAdvantage? A practical approach to adopting cloud, mobile, social and other trends A guided path to aligning IT more closely with business objectives Maximizing the value of existing investments in applications A layered approach to simplifying IT, building differentiation and bringing innovation All of the above? Enhance the value of your existing applications investment with #Oracle #AppAdvantage Aligning biz and IT expectations on Simplifying IT, building Differentiation and Innovation #AppAdvantage Adopt a pace layered approach to extracting biz value from your apps with #AppAdvantage Bringing #cloud, #social, #mobile to your apps with #Oracle #AppAdvantage Embracing Situational IT In the next IT Leaders Editorial, Rick Beers discusses the necessity of IT disruption and #AppAdvantage. Rick Beers sheds light on the Situational Leadership and the path to success #AppAdvantage. Rick Beers draws parallels with CIO’s strategic thinking and #Oracle #AppAdvantage approach. Do you have this paper in your summer reading list? Aligning biz and IT #AppAdvantage What does Situational leadership have to do with Oracle AppAdvantage? Catch the next piece in Rick Beers’ monthly series of IT Leaders Editorial and find out. #AppAdvantage Middleware Minutes with Howard Beader – August edition In the quarterly column, @hbeader discusses impact of #cloud, #mobile, #fastdata on #middleware Making #cloud, #mobile, #fastdata a part of your IT strategy with #middleware What keeps the #oracle #middleware team busy? Find out in the inaugural post in quarterly update on #middleware Recent #middleware news update along with a preview of things to come from #Oracle, in @hbeader ‘s quarterly column In his inaugural post, Howard Beader, senior director for Oracle Fusion Middleware, discusses the recent industry trends including mobile, cloud, fast data, integration and how these are shaping the IT and business requirements. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Mix Forum Technorati Tags: AppAdvantage,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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• Smart defaults [SSDT]

  - by jamiet

  I’ve just discovered a new, somewhat hidden, feature in SSDT that I didn’t know about and figured it would be worth highlighting here because I’ll bet not many others know it either; the feature is called Smart Defaults. It gets around the problem of adding a NOT NULLable column to an existing table that has got data in it – previous to SSDT you would need to define a DEFAULT constraint however it does feel rather cumbersome to create an object purely for the purpose of pushing through a deployment – that’s the situation that Smart Defaults is meant to alleviate. The Smart Defaults option exists in the advanced section of a Publish Profile file: The description of the setting is “Automatically provides a default value when updating a table that contains data with a column that does not allow null values”, in other words checking that option will cause SSDT to insert an arbitrary default value into your newly created NON NULLable column. In case you’re wondering how it does it, here’s how: SSDT creates a DEFAULT CONSTRAINT at the same time as the column is created and then immediately removes that constraint: ALTER TABLE [dbo].[T1]    ADD [C1] INT NOT NULL,         CONSTRAINT [SD_T1_1df7a5f76cf44bb593506d05ff9a1e2b] DEFAULT 0 FOR [C1];ALTER TABLE [dbo].[T1] DROP CONSTRAINT [SD_T1_1df7a5f76cf44bb593506d05ff9a1e2b]; You can then update the value as appropriate in a Post-Deployment script. Pretty cool! On the downside, you can only specify this option for the whole project, not for an individual table or even an individual column – I’m not sure that I’d want to turn this on for an entire project as it could hide problems that a failed deployment would highlight, in other words smart defaults could be seen to be “papering over the cracks”. If you think that should be improved go and vote (and leave a comment) at [SSDT] Allow us to specify Smart defaults per table or even per column. @Jamiet

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• How to read values from RESX file in ASP.NET using ResXResourceReader

  Here is the method which returns the value for a particular key in a given resource file. Below method assumes resourceFileName is the resource filename and key is the string for which the value has to be retrieved. public static string ReadValueFromResourceFile(String resourceFileName, String key)    {        String _value = String.Empty;        ResXResourceReader _resxReader = new ResXResourceReader(            String.Format("{0}{1}\\{2}",System.AppDomain.CurrentDomain.BaseDirectory.ToString(), StringConstants.ResourceFolderName , resourceFileName));        foreach (DictionaryEntry _item in _resxReader)        {            if (_item.Key.Equals(key))            {                _value = _item.Value.ToString();                break;            }        }        return _value;    } span.fullpost {display:none;}

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• links for 2010-03-18

  - by Bob Rhubart

  Oracle Database HA Architecture « The Oracle Instructor Oracle Certified Master Uwe Hesse introduces his blog's new Oracle Database HA Architecture page. (tags: oracle otn highavailability database) Mario Morgado: Where is the value of Enterprise Architecture? "When we purchase a product, its value is equivalent to the maximum amount that someone is willing to pay for the product. However, is the same equation valid in terms of the business value of enterprise architecture?" Mario Morgado (tags: otn oracle enterprisearchitecture) Steve Wilson: Managing Application to Disk "Of course, what we're introducing today goes beyond a mere re-skinning of Sun Ops Center. The promise is to offer real integration, and now we're delivering on the first phase in that roadmap by introducing the Oracle Management Connector for Ops Center. This software allows customers to connect an instance of Ops Center to an instance of Oracle Enterprise Manager's grid control server and connect the event streams of the two products, allowing for new levels of visibility into the customer's systems when using the combination of Oracle and Sun technology." "Virtual" Steve Wilson (tags: oraclesun opscenter)

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• Web Application: Combining View Layer Between PHP and Javascript-AJAX

  - by wlz

  I'm developing web application using PHP with CodeIgniter MVC framework with a huge real time client-side functionality needs. This is my first time to build large scale of client-side app. So I combine the PHP with a large scale of Javascript modules in one project. As you already know, MVC framework seperate application modules into Model-View-Controller. My concern is about View layer. I could be display the data on the DOM by PHP built-in script tag by load some data on the Controller. Otherwise I could use AJAX to pulled the data -- treat the Controller like a service only -- and display the them by Javascript. Here is some visualization I could put the data directly from Controller: <label>Username</label> <input type="text" id="username" value="<?=$userData['username'];?>"><br /> <label>Date of birth</label> <input type="text" id="dob" value="<?=$userData['dob'];?>"><br /> <label>Address</label> <input type="text" id="address" value="<?=$userData['address'];?>"> Or pull them using AJAX: $.ajax({ type: "POST", url: config.indexURL + "user", dataType: "json", success: function(data) { $('#username').val(data.username); $('#dateOfBirth').val(data.dob); $('#address').val(data.address); } }); So, which approach is better regarding my application has a complex client-side functionality? In the other hand, PHP-CI has a default mechanism to put the data directly from Controller, so why using AJAX?

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• SharePoint 2007 / 2010 Content Indexing &ldquo;The file reached the maximum download limit. Check that the full text of the document can be meaningfully crawled.&rdquo;

  - by Stacy Vicknair

  If you have large files in a content source that is being indexed by Sharepoint you might run into the following error message: “The file reached the maximum download limit. Check that the full text of the document can be meaningfully crawled.” This is usually caused because SharePoint’s MaxDownloadSize setting is set lower than the size of the file you are attempting to index. You can increase this value, restart the service then kick off a full crawl in order to fix this issue, but SharePoint 2007 and 2010 have different methods for accomplishing this task.   Sharepoint 2007 Open up the Registry editor and increase the MaxDownloadSize value to a number (in MB) higher than the largest file being indexed. You can find this at: HKEY_LOCAL_MACHINE\Software\Microsoft\Search\1.0\Gathering Manager After you increase the size, cycle the search service and kick off a full crawl of the content source in question.   Sharepoint 2010 With SharePoint 2010 you can use PowerShell via the Sharepoint 2010 Console in order to change the MaxDownloadSize. Execute the following commands to update the value: 1: $ssa = Get-SPEnterpriseSearchServiceApplication 2: $ssa.SetProperty(“MaxDownloadSize”, <new size in MB>) 3: $ssa.Update()   References: http://support.microsoft.com/kb/287231 http://blogs.technet.com/b/brent/archive/2010/07/19/sharepoint-server-2010-maxdownloadsize-and-maxgrowfactor.aspx   Technorati Tags: SharePoint,WSS,MaxDownloadSize,Search

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• Smart defaults [SSDT]

  - by jamiet

  I’ve just discovered a new, somewhat hidden, feature in SSDT that I didn’t know about and figured it would be worth highlighting here because I’ll bet not many others know it either; the feature is called Smart Defaults. It gets around the problem of adding a NOT NULLable column to an existing table that has got data in it – previous to SSDT you would need to define a DEFAULT constraint however it does feel rather cumbersome to create an object purely for the purpose of pushing through a deployment – that’s the situation that Smart Defaults is meant to alleviate. The Smart Defaults option exists in the advanced section of a Publish Profile file: The description of the setting is “Automatically provides a default value when updating a table that contains data with a column that does not allow null values”, in other words checking that option will cause SSDT to insert an arbitrary default value into your newly created NON NULLable column. In case you’re wondering how it does it, here’s how: SSDT creates a DEFAULT CONSTRAINT at the same time as the column is created and then immediately removes that constraint: ALTER TABLE [dbo].[T1]    ADD [C1] INT NOT NULL,         CONSTRAINT [SD_T1_1df7a5f76cf44bb593506d05ff9a1e2b] DEFAULT 0 FOR [C1];ALTER TABLE [dbo].[T1] DROP CONSTRAINT [SD_T1_1df7a5f76cf44bb593506d05ff9a1e2b]; You can then update the value as appropriate in a Post-Deployment script. Pretty cool! On the downside, you can only specify this option for the whole project, not for an individual table or even an individual column – I’m not sure that I’d want to turn this on for an entire project as it could hide problems that a failed deployment would highlight, in other words smart defaults could be seen to be “papering over the cracks”. If you think that should be improved go and vote (and leave a comment) at [SSDT] Allow us to specify Smart defaults per table or even per column. @Jamiet

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• Why Oracle Data Integrator for Big Data?

  - by Mala Narasimharajan

  Big Data is everywhere these days - but what exactly is it? It’s data that comes from a multitude of sources – not only structured data, but unstructured data as well.  The sheer volume of data is mindboggling – here are a few examples of big data: climate information collected from sensors, social media information, digital pictures, log files, online video files, medical records or online transaction records.  These are just a few examples of what constitutes big data.   Embedded in big data is tremendous value and being able to manipulate, load, transform and analyze big data is key to enhancing productivity and competitiveness.  The value of big data lies in its propensity for greater in-depth analysis and data segmentation -- in turn giving companies detailed information on product performance, customer preferences and inventory.  Furthermore, by being able to store and create more data in digital form, “big data can unlock significant value by making information transparent and usable at much higher frequency." (McKinsey Global Institute, May 2011) Oracle's flagship product for bulk data movement and transformation, Oracle Data Integrator, is a critical component of Oracle’s Big Data strategy. ODI provides automation, bulk loading, and validation and transformation capabilities for Big Data while minimizing the complexities of using Hadoop.  Specifically, the advantages of ODI in a Big Data scenario are due to pre-built Knowledge Modules that drive processing in Hadoop. This leverages the graphical UI to load and unload data from Hadoop, perform data validations and create mapping expressions for transformations.  The Knowledge Modules provide a key jump-start and eliminate a significant amount of Hadoop development.  Using Oracle Data Integrator together with Oracle Big Data Connectors, you can simplify the complexities of mapping, accessing, and loading big data (via NoSQL or HDFS) but also correlating your enterprise data – this correlation may require integrating across heterogeneous and standards-based environments, connecting to Oracle Exadata, or sourcing via a big data platform such as Oracle Big Data Appliance. To learn more about Oracle Data Integration and Big Data, download our resource kit to see the latest in whitepapers, webinars, downloads, and more… or go to our website on www.oracle.com/bigdata

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• Command-Query-Separation and multithreading safe interfaces

  - by Tobias Langner

  I like the command query separation pattern (from OOSC / Eiffel - basically you either return a value or you change the state of the class - but not both). This makes reasoning about the class easier and it is easier to write exception safe classes. Now, with multi threading, I run into a major problem: the separation of the query and the command basically invalidates the result from the query as anything can happen between those 2. So my question is: how do you handle command query separation in an multi-threaded environment? Clarification example: A stack with command query separation would have the following methods: push (command) pop (command - but does not return a value) top (query - returns the value) empty (query) The problem here is - I can get empty as status, but then I can not rely on top really retrieving an element since between the call of empty and the call of top, the stack might have been emptied. Same goes for pop & top. If I get an item using top, I can not be sure that the item that I pop is the same. This can be solved using external locks - but that's not exactly what I call threadsafe design.

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• Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG (Doc ID 1594372.1)

  - by user702295

  Hello!   There is a new document available: Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG (Doc ID 1594372.1) Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG The table reorganization can be setup to automatically run in version 7.3.1.5.  In version 12.2.2 we run the TABLE_REORG.CHECK_REORG function at every appserver restart. If the function recommends a reorg then we strongly encourage to reorg the database object.  This is documented in the official docs. In versions 7.3.1.3 and 7.3.1.4, the TABLE_REORG module exists and can be used. It has two main functions that are documented in the Implementation Guide Supplement, Release 7.3, Part No. E26760-03, chapter 4. In short, if you are using version 7.3.1.3 or higher, you can check for the need to run a reorg by doing the following 2 steps: 1. Run TABLE_REORG.CHECK_REORG('T'); 2. Check the table LOG_TABLE_REORG for recommendations If you are on a version before 7.3.1.3, you will need to follow the instructions below to determine if you need to do a manual reorg. How to determine if a table reorg is needed 1. It is strongly encouraged by DEV that You gather statistics on the required table.  The prefered percentage for the gather is 100%. 2. Run the following SQL to evaluate how table reorg might affect Primary Key (PK) based access:   SELECT ui.index_name,trunc((ut.num_rows/ui.clustering_factor)/(ut.num_rows/ut.blocks),2) FROM user_indexes ui, user_tables ut, user_constraints uc WHERE ui.table_name=ut.table_name AND ut.table_name=uc.table_name AND ui.index_name=uc.index_name AND UC.CONSTRAINT_TYPE='P' AND ut.table_name=upper('&enter_table_name');   3. Based on the result: VALUE ABOVE 0.75 - DOES NOT REQUIRE REORG VALUE BETWEEN 0.5 AND 0.75 - REORG IS RECOMMENDED VALUE LOWER THAN 0.5 - IT IS HIGHLY RECOMMENDED TO REORG

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• Loading the Cache from the Business Application Server

  - by ACShorten

  By default, the Web Application server will directly connect to the Database to load its cache at startup time. Customers, who implement the product installation in distributed mode, where the Web Application Server and Business Application Server are deployed separately, may wish to prevent the Web Application Server to connect to the database directly. Installation of the product in distributed mode was introduced in Oracle Utilities Application Framework V2.2. In the Advanced Web Application Server configuration, it is possible to set the Create Simple Web Application Context (WEBAPPCONTEXT) to true to force the Web Application Server to load its cache via the Business Application rather than direct loading. The value of false will retain the default behavior of allowing the Web Application Server to connect directly to the database at startup time to load the cache. The value of true will load the cache data via direct calls to the Business Application Server, which can cause a slight delay in the startup process to cater for the architecture load rather than the direct load. The impact of the settings is illustrated in the figure below:                             When setting this value to true, the following properties files should be manually removed prior to executing the product: $SPLEBASE/etc/conf/root/WEB-INF/classes/hibernate.properties $SPLEBASE/splapp/applications/root/WEB-INF/classes/hibernate.properties Note: For customers who are using a local installation, where the Web Application Server and Business Application Server are combined in the deployed server, it is recommended to set this parameter to false, the default, unless otherwise required. This facility is available for Oracle Utilities Application Framework V4.1 in Group Fix 3 (via Patch 11900153) and Patch 13538242 available from My Oracle Support.

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• New Enhancements for InnoDB Memcached

  - by Calvin Sun

  In MySQL 5.6, we continued our development on InnoDB Memcached and completed a few widely desirable features that make InnoDB Memcached a competitive feature in more scenario. Notablely, they are 1) Support multiple table mapping 2) Added background thread to auto-commit long running transactions 3) Enhancement in binlog performance  Let’s go over each of these features one by one. And in the last section, we will go over a couple of internally performed performance tests. Support multiple table mapping In our earlier release, all InnoDB Memcached operations are mapped to a single InnoDB table. In the real life, user might want to use this InnoDB Memcached features on different tables. Thus being able to support access to different table at run time, and having different mapping for different connections becomes a very desirable feature. And in this GA release, we allow user just be able to do both. We will discuss the key concepts and key steps in using this feature. 1) "mapping name" in the "get" and "set" command In order to allow InnoDB Memcached map to a new table, the user (DBA) would still require to "pre-register" table(s) in InnoDB Memcached “containers” table (there is security consideration for this requirement). If you would like to know about “containers” table, please refer to my earlier blogs in blogs.innodb.com. Once registered, the InnoDB Memcached will then be able to look for such table when they are referred. Each of such registered table will have a unique "registration name" (or mapping_name) corresponding to the “name” field in the “containers” table.. To access these tables, user will include such "registration name" in their get or set commands, in the form of "get @@new_mapping_name.key", prefix "@@" is required for signaling a mapped table change. The key and the "mapping name" are separated by a configurable delimiter, by default, it is ".". So the syntax is: get [@@mapping_name.]key_name set [@@mapping_name.]key_name  or  get @@mapping_name set @@mapping_name Here is an example: Let's set up three tables in the "containers" table: The first is a map to InnoDB table "test/demo_test" table with mapping name "setup_1" INSERT INTO containers VALUES ("setup_1", "test", "demo_test", "c1", "c2", "c3", "c4", "c5", "PRIMARY");  Similarly, we set up table mappings for table "test/new_demo" with name "setup_2" and that to table "mydatabase/my_demo" with name "setup_3": INSERT INTO containers VALUES ("setup_2", "test", "new_demo", "c1", "c2", "c3", "c4", "c5", "secondary_index_x"); INSERT INTO containers VALUES ("setup_3", "my_database", "my_demo", "c1", "c2", "c3", "c4", "c5", "idx"); To switch to table "my_database/my_demo", and get the value corresponding to “key_a”, user will do: get @@setup_3.key_a (this will also output the value that corresponding to key "key_a" or simply get @@setup_3 Once this is done, this connection will switch to "my_database/my_demo" table until another table mapping switch is requested. so it can continue issue regular command like: get key_b  set key_c 0 0 7 These DMLs will all be directed to "my_database/my_demo" table. And this also implies that different connections can have different bindings (to different table). 2) Delimiter: For the delimiter "." that separates the "mapping name" and key value, we also added a configure option in the "config_options" system table with name of "table_map_delimiter": INSERT INTO config_options VALUES("table_map_delimiter", "."); So if user wants to change to a different delimiter, they can change it in the config_option table. 3) Default mapping: Once we have multiple table mapping, there should be always a "default" map setting. For this, we decided if there exists a mapping name of "default", then this will be chosen as default mapping. Otherwise, the first row of the containers table will chosen as default setting. Please note, user tables can be repeated in the "containers" table (for example, user wants to access different columns of the table in different settings), as long as they are using different mapping/configure names in the first column, which is enforced by a unique index. 4) bind command In addition, we also extend the protocol and added a bind command, its usage is fairly straightforward. To switch to "setup_3" mapping above, you simply issue: bind setup_3 This will switch this connection's InnoDB table to "my_database/my_demo" In summary, with this feature, you now can direct access to difference tables with difference session. And even a single connection, you can query into difference tables. Background thread to auto-commit long running transactions This is a feature related to the “batch” concept we discussed in earlier blogs. This “batch” feature allows us batch the read and write operations, and commit them only after certain calls. The “batch” size is controlled by the configure parameter “daemon_memcached_w_batch_size” and “daemon_memcached_r_batch_size”. This could significantly boost performance. However, it also comes with some disadvantages, for example, you will not be able to view “uncommitted” operations from SQL end unless you set transaction isolation level to read_uncommitted, and in addition, this will held certain row locks for extend period of time that might reduce the concurrency. To deal with this, we introduce a background thread that “auto-commits” the transaction if they are idle for certain amount of time (default is 5 seconds). The background thread will wake up every second and loop through every “connections” opened by Memcached, and check for idle transactions. And if such transaction is idle longer than certain limit and not being used, it will commit such transactions. This limit is configurable by change “innodb_api_bk_commit_interval”. Its default value is 5 seconds, and minimum is 1 second, and maximum is 1073741824 seconds. With the help of such background thread, you will not need to worry about long running uncommitted transactions when set daemon_memcached_w_batch_size and daemon_memcached_r_batch_size to a large number. This also reduces the number of locks that could be held due to long running transactions, and thus further increase the concurrency. Enhancement in binlog performance As you might all know, binlog operation is not done by InnoDB storage engine, rather it is handled in the MySQL layer. In order to support binlog operation through InnoDB Memcached, we would have to artificially create some MySQL constructs in order to access binlog handler APIs. In previous lab release, for simplicity consideration, we open and destroy these MySQL constructs (such as THD) for each operations. This required us to set the “batch” size always to 1 when binlog is on, no matter what “daemon_memcached_w_batch_size” and “daemon_memcached_r_batch_size” are configured to. This put a big restriction on our capability to scale, and also there are quite a bit overhead in creating destroying such constructs that bogs the performance down. With this release, we made necessary change that would keep MySQL constructs as long as they are valid for a particular connection. So there will not be repeated and redundant open and close (table) calls. And now even with binlog option is enabled (with innodb_api_enable_binlog,), we still can batch the transactions with daemon_memcached_w_batch_size and daemon_memcached_r_batch_size, thus scale the write/read performance. Although there are still overheads that makes InnoDB Memcached cannot perform as fast as when binlog is turned off. It is much better off comparing to previous release. And we are continuing optimize the solution is this area to improve the performance as much as possible. Performance Study: Amerandra of our System QA team have conducted some performance studies on queries through our InnoDB Memcached connection and plain SQL end. And it shows some interesting results. The test is conducted on a “Linux 2.6.32-300.7.1.el6uek.x86_64 ix86 (64)” machine with 16 GB Memory, Intel Xeon 2.0 GHz CPU X86_64 2 CPUs- 4 Core Each, 2 RAID DISKS (1027 GB,733.9GB). Results are described in following tables: Table 1: Performance comparison on Set operations Connections 5.6.7-RC-Memcached-plugin ( TPS / Qps) with memcached-threads=8*** 5.6.7-RC* X faster Set (QPS) Set** 8 30,000 5,600 5.36 32 59,000 13,000 4.54 128 68,000 8,000 8.50 512 63,000 6.800 9.23 * mysql-5.6.7-rc-linux2.6-x86_64 ** The “set” operation when implemented in InnoDB Memcached involves a couple of DMLs: it first query the table to see whether the “key” exists, if it does not, the new key/value pair will be inserted. If it does exist, the “value” field of matching row (by key) will be updated. So when used in above query, it is a precompiled store procedure, and query will just execute such procedures. *** added “–daemon_memcached_option=-t8” (default is 4 threads) So we can see with this “set” query, InnoDB Memcached can run 4.5 to 9 time faster than MySQL server. Table 2: Performance comparison on Get operations Connections 5.6.7-RC-Memcached-plugin ( TPS / Qps) with memcached-threads=8 5.6.7-RC* X faster Get (QPS) Get 8 42,000 27,000 1.56 32 101,000 55.000 1.83 128 117,000 52,000 2.25 512 109,000 52,000 2.10 With the “get” query (or the select query), memcached performs 1.5 to 2 times faster than normal SQL. Summary: In summary, we added several much-desired features to InnoDB Memcached in this release, allowing user to operate on different tables with this Memcached interface. We also now provide a background commit thread to commit long running idle transactions, thus allow user to configure large batch write/read without worrying about large number of rows held or not being able to see (uncommit) data. We also greatly enhanced the performance when Binlog is enabled. We will continue making efforts in both performance enhancement and functionality areas to make InnoDB Memcached a good demo case for our InnoDB APIs. Jimmy Yang, September 29, 2012

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• C#/.NET Little Wonders: The Nullable static class

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Today we’re going to look at an interesting Little Wonder that can be used to mitigate what could be considered a Little Pitfall.  The Little Wonder we’ll be examining is the System.Nullable static class.  No, not the System.Nullable<T> class, but a static helper class that has one useful method in particular that we will examine… but first, let’s look at the Little Pitfall that makes this wonder so useful. Little Pitfall: Comparing nullable value types using <, >, <=, >= Examine this piece of code, without examining it too deeply, what’s your gut reaction as to the result? 1: int? x = null; 2:  3: if (x < 100) 4: { 5: Console.WriteLine("True, {0} is less than 100.", 6: x.HasValue ? x.ToString() : "null"); 7: } 8: else 9: { 10: Console.WriteLine("False, {0} is NOT less than 100.", 11: x.HasValue ? x.ToString() : "null"); 12: } Your gut would be to say true right?  It would seem to make sense that a null integer is less than the integer constant 100.  But the result is actually false!  The null value is not less than 100 according to the less-than operator. It looks even more outrageous when you consider this also evaluates to false: 1: int? x = null; 2:  3: if (x < int.MaxValue) 4: { 5: // ... 6: } So, are we saying that null is less than every valid int value?  If that were true, null should be less than int.MinValue, right?  Well… no: 1: int? x = null; 2:  3: // um... hold on here, x is NOT less than min value? 4: if (x < int.MinValue) 5: { 6: // ... 7: } So what’s going on here?  If we use greater than instead of less than, we see the same little dilemma: 1: int? x = null; 2:  3: // once again, null is not greater than anything either... 4: if (x > int.MinValue) 5: { 6: // ... 7: } It turns out that four of the comparison operators (<, <=, >, >=) are designed to return false anytime at least one of the arguments is null when comparing System.Nullable wrapped types that expose the comparison operators (short, int, float, double, DateTime, TimeSpan, etc.).  What’s even odder is that even though the two equality operators (== and !=) work correctly, >= and <= have the same issue as < and > and return false if both System.Nullable wrapped operator comparable types are null! 1: DateTime? x = null; 2: DateTime? y = null; 3:  4: if (x <= y) 5: { 6: Console.WriteLine("You'd think this is true, since both are null, but it's not."); 7: } 8: else 9: { 10: Console.WriteLine("It's false because <=, <, >, >= don't work on null."); 11: } To make matters even more confusing, take for example your usual check to see if something is less than, greater to, or equal: 1: int? x = null; 2: int? y = 100; 3:  4: if (x < y) 5: { 6: Console.WriteLine("X is less than Y"); 7: } 8: else if (x > y) 9: { 10: Console.WriteLine("X is greater than Y"); 11: } 12: else 13: { 14: // We fall into the "equals" assumption, but clearly null != 100! 15: Console.WriteLine("X is equal to Y"); 16: } Yes, this code outputs “X is equal to Y” because both the less-than and greater-than operators return false when a Nullable wrapped operator comparable type is null.  This violates a lot of our assumptions because we assume is something is not less than something, and it’s not greater than something, it must be equal.  So keep in mind, that the only two comparison operators that work on Nullable wrapped types where at least one is null are the equals (==) and not equals (!=) operators: 1: int? x = null; 2: int? y = 100; 3:  4: if (x == y) 5: { 6: Console.WriteLine("False, x is null, y is not."); 7: } 8:  9: if (x != y) 10: { 11: Console.WriteLine("True, x is null, y is not."); 12: } Solution: The Nullable static class So we’ve seen that <, <=, >, and >= have some interesting and perhaps unexpected behaviors that can trip up a novice developer who isn’t expecting the kinks that System.Nullable<T> types with comparison operators can throw.  How can we easily mitigate this? Well, obviously, you could do null checks before each check, but that starts to get ugly: 1: if (x.HasValue) 2: { 3: if (y.HasValue) 4: { 5: if (x < y) 6: { 7: Console.WriteLine("x < y"); 8: } 9: else if (x > y) 10: { 11: Console.WriteLine("x > y"); 12: } 13: else 14: { 15: Console.WriteLine("x == y"); 16: } 17: } 18: else 19: { 20: Console.WriteLine("x > y because y is null and x isn't"); 21: } 22: } 23: else if (y.HasValue) 24: { 25: Console.WriteLine("x < y because x is null and y isn't"); 26: } 27: else 28: { 29: Console.WriteLine("x == y because both are null"); 30: } Yes, we could probably simplify this logic a bit, but it’s still horrendous!  So what do we do if we want to consider null less than everything and be able to properly compare Nullable<T> wrapped value types? The key is the System.Nullable static class.  This class is a companion class to the System.Nullable<T> class and allows you to use a few helper methods for Nullable<T> wrapped types, including a static Compare<T>() method of the. What’s so big about the static Compare<T>() method?  It implements an IComparer compatible comparison on Nullable<T> types.  Why do we care?  Well, if you look at the MSDN description for how IComparer works, you’ll read: Comparing null with any type is allowed and does not generate an exception when using IComparable. When sorting, null is considered to be less than any other object. This is what we probably want!  We want null to be less than everything!  So now we can change our logic to use the Nullable.Compare<T>() static method: 1: int? x = null; 2: int? y = 100; 3:  4: if (Nullable.Compare(x, y) < 0) 5: { 6: // Yes! x is null, y is not, so x is less than y according to Compare(). 7: Console.WriteLine("x < y"); 8: } 9: else if (Nullable.Compare(x, y) > 0) 10: { 11: Console.WriteLine("x > y"); 12: } 13: else 14: { 15: Console.WriteLine("x == y"); 16: } Summary So, when doing math comparisons between two numeric values where one of them may be a null Nullable<T>, consider using the System.Nullable.Compare<T>() method instead of the comparison operators.  It will treat null less than any value, and will avoid logic consistency problems when relying on < returning false to indicate >= is true and so on. Tweet   Technorati Tags: C#,C-Sharp,.NET,Little Wonders,Little Pitfalls,Nulalble

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• Model won't render in my XNA game

  - by Daniel Lopez

  I am trying to create a simple 3D game but things aren't working out as they should. For instance, the mode will not display. I created a class that does the rendering so I think that is where the problem lies. P.S I am using models from the MSDN website so I know the models are compatible with XNA. Code: class ModelRenderer { private float aspectratio; private Model model; private Vector3 camerapos; private Vector3 modelpos; private Matrix rotationy; float radiansy = 0; public ModelRenderer(Model m, float AspectRatio, Vector3 initial_pos, Vector3 initialcamerapos) { model = m; if (model.Meshes.Count == 0) { throw new Exception("Invalid model because it contains zero meshes!"); } modelpos = initial_pos; camerapos = initialcamerapos; aspectratio = AspectRatio; return; } public Vector3 CameraPosition { set { camerapos = value; } get { return camerapos; } } public Vector3 ModelPosition { set { modelpos = value; } get { return modelpos; } } public void RotateY(float radians) { radiansy += radians; rotationy = Matrix.CreateRotationY(radiansy); } public float AspectRatio { set { aspectratio = value; } get { return aspectratio; } } public void Draw() { Matrix world = Matrix.CreateTranslation(modelpos) * rotationy; Matrix view = Matrix.CreateLookAt(this.CameraPosition, this.ModelPosition, Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), this.AspectRatio, 1.0f, 10000f); model.Draw(world, view, projection); } } If you need more code just make a comment.

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• DB2 on SPARC T3 Tuning Tips

  - by cherry.shu(at)oracle.com

  With the new self tuning feature in DB2 V9.x, a lot of database parameters are set to automatic in DB2 v9.7 by default so that DB2 can adjust the values as needed. Most should work fine without manual tweaks. But for transaction workload on SPARC T3 systems, two parameters need to be adjust manually to achieve optimal performance. DATABASE_MEMORY: When this parameter is set to AUTOMATIC and SELF_TUNING_MEM is set to ON, DB2 will allocate small page size (64KB) for all memory allocation, and expands and shrinks the memory as needed. In order to take advantage of the large page size (up to 256MB) supported by the SPARC T3, we need to manually set the size of the DATABASE_MEMORY so that DB2 can use 256MB page size for its buffer pools which are implemented as ISM segments. I know this sounds strange as it seems that you turn a switch and it ends up controlling another function. pmap(1M) output can verify the page sizes used by DB2 db2sysc process. NUM_IOCLEANERS: This parameter defines the number of page cleaners. The default value of this parameter is AUTOMATIC, which is calculated based on the number of available CPUs and the number of logical partitions. On a SPARC T3 system where there are over a hundred of virtual CPUs and single DB2 partition, DB2 would set it to #CPUs - 1. This would lead to too many page cleaners to compete flushing to disks and cause aio mutex lock contentions. So we need to decrease the value for it. The good practice is to set the value to the number of physical devices that are used by the database table space containers.

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• jQuery CSS Property Monitoring Plug-in updated

  - by Rick Strahl

  A few weeks back I had talked about the need to watch properties of an object and be able to take action when certain values changed. The need for this arose out of wanting to build generic components that could 'attach' themselves to other objects. One example is a drop shadow - if I add a shadow behavior to an object I want the shadow to be pinned to that object so when that object moves I also want the shadow to move with it, or when the panel is hidden the shadow should hide with it - automatically without having to explicitly hook up monitoring code to the panel. For example, in my shadow plug-in I can now do something like this (where el is the element that has the shadow attached and sh is the shadow): if (!exists) // if shadow was created el.watch("left,top,width,height,display", function() { if (el.is(":visible")) $(this).shadow(opt); // redraw else sh.hide(); }, 100, "_shadowMove"); The code now monitors several properties and if any of them change the provided function is called. So when the target object is moved or hidden or resized the watcher function is called and the shadow can be redrawn or hidden in the case of visibility going away. So if you run any of the following code: $("#box") .shadow() .draggable({ handle: ".blockheader" }); // drag around the box - shadow should follow // hide the box - shadow should disappear with box setTimeout(function() { $("#box").hide(); }, 4000); // show the box - shadow should come back too setTimeout(function() { $("#box").show(); }, 8000); This can be very handy functionality when you're dealing with objects or operations that you need to track generically and there are no native events for them. For example, with a generic shadow object that attaches itself to any another element there's no way that I know of to track whether the object has been moved or hidden either via some UI operation (like dragging) or via code. While some UI operations like jQuery.ui.draggable would allow events to fire when the mouse is moved nothing of the sort exists if you modify locations in code. Even tracking the object in drag mode this is hardly generic behavior - a generic shadow implementation can't know when dragging is hooked up. So the watcher provides an alternative that basically gives an Observer like pattern that notifies you when something you're interested in changes. In the watcher hookup code (in the shadow() plugin) above  a check is made if the object is visible and if it is the shadow is redrawn. Otherwise the shadow is hidden. The first parameter is a list of CSS properties to be monitored followed by the function that is called. The function called receives this as the element that's been changed and receives two parameters: The array of watched objects with their current values, plus an index to the object that caused the change function to fire. How does it work When I wrote it about this last time I started out with a simple timer that would poll for changes at a fixed interval with setInterval(). A few folks commented that there are is a DOM API - DOMAttrmodified in Mozilla and propertychange in IE that allow notification whenever any property changes which is much more efficient and smooth than the setInterval approach I used previously. On browser that support these events (FireFox and IE basically - WebKit has the DOMAttrModified event but it doesn't appear to work) the shadow effect is instant - no 'drag behind' of the shadow. Running on a browser that doesn't support still uses setInterval() and the shadow movement is slightly delayed which looks sloppy. There are a few additional changes to this code - it also supports monitoring multiple CSS properties now so a single object can monitor a host of CSS properties rather than one object per property which is easier to work with. For display purposes position, bounds and visibility will be common properties that are to be watched. Here's what the new version looks like: $.fn.watch = function (props, func, interval, id) { /// <summary> /// Allows you to monitor changes in a specific /// CSS property of an element by polling the value. /// when the value changes a function is called. /// The function called is called in the context /// of the selected element (ie. this) /// </summary> /// <param name="prop" type="String">CSS Properties to watch sep. by commas</param> /// <param name="func" type="Function"> /// Function called when the value has changed. /// </param> /// <param name="interval" type="Number"> /// Optional interval for browsers that don't support DOMAttrModified or propertychange events. /// Determines the interval used for setInterval calls. /// </param> /// <param name="id" type="String">A unique ID that identifies this watch instance on this element</param> /// <returns type="jQuery" /> if (!interval) interval = 200; if (!id) id = "_watcher"; return this.each(function () { var _t = this; var el$ = $(this); var fnc = function () { __watcher.call(_t, id) }; var itId = null; var data = { id: id, props: props.split(","), func: func, vals: [props.split(",").length], fnc: fnc, origProps: props, interval: interval }; $.each(data.props, function (i) { data.vals[i] = el$.css(data.props[i]); }); el$.data(id, data); hookChange(el$, id, data.fnc); }); function hookChange(el$, id, fnc) { el$.each(function () { var el = $(this); if (typeof (el.get(0).onpropertychange) == "object") el.bind("propertychange." + id, fnc); else if ($.browser.mozilla) el.bind("DOMAttrModified." + id, fnc); else itId = setInterval(fnc, interval); }); } function __watcher(id) { var el$ = $(this); var w = el$.data(id); if (!w) return; var _t = this; if (!w.func) return; // must unbind or else unwanted recursion may occur el$.unwatch(id); var changed = false; var i = 0; for (i; i < w.props.length; i++) { var newVal = el$.css(w.props[i]); if (w.vals[i] != newVal) { w.vals[i] = newVal; changed = true; break; } } if (changed) w.func.call(_t, w, i); // rebind event hookChange(el$, id, w.fnc); } } $.fn.unwatch = function (id) { this.each(function () { var el = $(this); var fnc = el.data(id).fnc; try { if (typeof (this.onpropertychange) == "object") el.unbind("propertychange." + id, fnc); else if ($.browser.mozilla) el.unbind("DOMAttrModified." + id, fnc); else clearInterval(id); } // ignore if element was already unbound catch (e) { } }); return this; } There are basically two jQuery functions - watch and unwatch. jQuery.fn.watch(props,func,interval,id) Starts watching an element for changes in the properties specified. props The CSS properties that are to be watched for changes. If any of the specified properties changes the function specified in the second parameter is fired. func (watchData,index) The function fired in response to a changed property. Receives this as the element changed and object that represents the watched properties and their respective values. The first parameter is passed in this structure:    { id: itId, props: [], func: func, vals: [] }; A second parameter is the index of the changed property so data.props[i] or data.vals[i] gets the property value that has changed. interval The interval for setInterval() for those browsers that don't support property watching in the DOM. In milliseconds. id An optional id that identifies this watcher. Required only if multiple watchers might be hooked up to the same element. The default is _watcher if not specified. jQuery.fn.unwatch(id) Unhooks watching of the element by disconnecting the event handlers. id Optional watcher id that was specified in the call to watch. This value can be omitted to use the default value of _watcher. You can also grab the latest version of the  code for this plug-in as well as the shadow in the full library at: http://www.west-wind.com:8080/svn/jquery/trunk/jQueryControls/Resources/ww.jquery.js watcher has no other dependencies although it lives in this larger library. The shadow plug-in depends on watcher.© Rick Strahl, West Wind Technologies, 2005-2011

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• .NET Properties - Use Private Set or ReadOnly Property?

  - by tgxiii

  In what situation should I use a Private Set on a property versus making it a ReadOnly property? Take into consideration the two very simplistic examples below. First example: Public Class Person Private _name As String Public Property Name As String Get Return _name End Get Private Set(ByVal value As String) _name = value End Set End Property Public Sub WorkOnName() Dim txtInfo As TextInfo = _ Threading.Thread.CurrentThread.CurrentCulture.TextInfo Me.Name = txtInfo.ToTitleCase(Me.Name) End Sub End Class // ---------- public class Person { private string _name; public string Name { get { return _name; } private set { _name = value; } } public void WorkOnName() { TextInfo txtInfo = System.Threading.Thread.CurrentThread.CurrentCulture.TextInfo; this.Name = txtInfo.ToTitleCase(this.Name); } } Second example: Public Class AnotherPerson Private _name As String Public ReadOnly Property Name As String Get Return _name End Get End Property Public Sub WorkOnName() Dim txtInfo As TextInfo = _ Threading.Thread.CurrentThread.CurrentCulture.TextInfo _name = txtInfo.ToTitleCase(_name) End Sub End Class // --------------- public class AnotherPerson { private string _name; public string Name { get { return _name; } } public void WorkOnName() { TextInfo txtInfo = System.Threading.Thread.CurrentThread.CurrentCulture.TextInfo; _name = txtInfo.ToTitleCase(_name); } } They both yield the same results. Is this a situation where there's no right and wrong, and it's just a matter of preference?

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• What is the best practice for when to check if something needs to be done?

  - by changokun

  Let's say I have a function that does x. I pass it a variable, and if the variable is not null, it does some action. And I have an array of variables and I'm going to run this function on each one. Inside the function, it seems like a good practice is to check if the argument is null before proceeding. A null argument is not an error, it just causes an early return. I could loop through the array and pass each value to the function, and the function will work great. Is there any value to checking if the var is null and only calling the function if it is not null during the loop? This doubles up on the checking for null, but: Is there any gained value? Is there any gain on not calling a function? Any readability gain on the loop in the parent code? For the sake of my question, let's assume that checking for null will always be the case. I can see how checking for some object property might change over time, which makes the first check a bad idea. Pseudo code example: for(thing in array) { x(thing) } Versus: for(thing in array) { if(thing not null) x(thing) } If there are language-specific concerns, I'm a web developer working in PHP and JavaScript.

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• Getting codebaseHQ SVN ChangeLog data in your application

  - by saifkhan

  I deploy apps via ClickOnce. After each deployment we have to review the changes made and send out an email to the users with the changes. What I decided now to do is to use CodebaseHQ’s API to access a project’s SVN repository and display the commit notes so some users who download new updates can check what was changed or updated in an app. This saves a heck of a lot of time, especially when your apps are in beta and you are making several changes daily based on feedback. You can read up on their API here Here is a sample on how to access the Repositories API from a windows app Public Sub GetLog() If String.IsNullOrEmpty(_url) Then Exit Sub Dim answer As String = String.Empty Dim myReq As HttpWebRequest = WebRequest.Create(_url) With myReq .Headers.Add("Authorization", String.Format("Basic {0}", Convert.ToBase64String(Encoding.ASCII.GetBytes("username:password")))) .ContentType = "application/xml" .Accept = "application/xml" .Method = "POST" End With Try Using response As HttpWebResponse = myReq.GetResponse() Using sr As New System.IO.StreamReader(response.GetResponseStream()) answer = sr.ReadToEnd() Dim doc As XDocument = XDocument.Parse(answer) Dim commits = From commit In doc.Descendants("commit") _ Select Message = commit.Element("message").Value, _ AuthorName = commit.Element("author-name").Value, _ AuthoredDate = DateTime.Parse(commit.Element("authored-at").Value).Date grdLogData.BeginUpdate() grdLogData.DataSource = commits.ToList() grdLogData.EndUpdate() End Using End Using Catch ex As Exception MsgBox(ex.Message) End Try End Sub

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• ASP.NET ViewState Tips and Tricks #1

  - by João Angelo

  In User Controls or Custom Controls DO NOT use ViewState to store non public properties. Persisting non public properties in ViewState results in loss of functionality if the Page hosting the controls has ViewState disabled since it can no longer reset values of non public properties on page load. Example: public class ExampleControl : WebControl { private const string PublicViewStateKey = "Example_Public"; private const string NonPublicViewStateKey = "Example_NonPublic"; // DO public int Public { get { object o = this.ViewState[PublicViewStateKey]; if (o == null) return default(int); return (int)o; } set { this.ViewState[PublicViewStateKey] = value; } } // DO NOT private int NonPublic { get { object o = this.ViewState[NonPublicViewStateKey]; if (o == null) return default(int); return (int)o; } set { this.ViewState[NonPublicViewStateKey] = value; } } } // Page with ViewState disabled public partial class ExamplePage : Page { protected override void OnLoad(EventArgs e) { base.OnLoad(e); this.Example.Public = 10; // Restore Public value this.Example.NonPublic = 20; // Compile Error! } }

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• New Certification Exam Prep Seminar: Java EE 5/6 Web Component Developer

  - by Brandye Barrington

  I'm happy to announce the availability of a brand new Exam Prep Seminar titled Certification Exam Prep Seminar: Java EE 5/6 Web Component Developer. This new Exam Prep Seminar is available standalone, and will soon be available through a Certification Value Package, which includes (1) the Seminar, and (2) a certification exam voucher with a free retake. For those of you preparing for the Oracle Certified Professional, Java EE 5 Web Component Developer certification or the Oracle Certified Expert, Java Platform, EE 6 Web Component Developer certification, this seminar is a great value and and an excellent way to gain valuable insight from one of Oracle University's top instructors. This Exam Prep Seminar will accelerate your preparation, make your prep time more efficient and give you insight to the breadth and depth of the certification exam. This type of exam preparation has traditionally only been available at the Oracle OpenWorld conference, but is now available to anyone through this new format. Of course with online video, you can now start, stop, rewind, and review as needed! Also note that because this seminar is in the Oracle Training On Demand format, you can also watch it on your your iPad through Oracle University's new free iPad app. QUICK LINKS SEMINAR: Certification Exam Prep Seminar: Java EE 5/6 Web Component Developer VALUE PACKAGE: Coming Soon! EXAM: 1Z0-858  Java Enterprise Edition 5 Web Component Developer Certified Professional Exam EXAM: 1Z0-859  Java Enterprise Edition 5 Web Component Developer Certified Professional Upgrade Exam EXAM: 1Z0-899  Java EE 6 Web Component Developer Certified Expert Exam CERTIFICATION: Oracle Certified Professional, Java EE 5 Web Component Developer CERTIFICATION: Oracle Certified Expert, Java Platform, EE 6 Web Component Developer

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• Is NAN suitable for communicating that an invalid parameter was involved in a calculation?

  - by Arman

  I am currently working on a numerical processing system that will be deployed in a performance-critical environment. It takes inputs in the form of numerical arrays (these use the eigen library, but for the purpose of this question that's perhaps immaterial), and performs some range of numerical computations (matrix products, concatenations, etc.) to produce outputs. All arrays are allocated statically and their sizes are known at compile time. However, some of the inputs may be invalid. In these exceptional cases, we still want the code to be computed and we still want outputs not "polluted" by invalid values to be used. To give an example, let's take the following trivial example (this is pseudo-code): Matrix a = {1, 2, NAN, 4}; // this is the "input" matrix Scalar b = 2; Matrix output = b * a; // this results in {2, 4, NAN, 8} The idea here is that 2, 4 and 8 are usable values, but the NAN should signal to the receipient of the data that that entry was involved in an operation that involved an invalid value, and should be discarded (this will be detected via a std::isfinite(value) check before the value is used). Is this a sound way of communicating and propagating unusable values, given that performance is critical and heap allocation is not an option (and neither are other resource-consuming constructs such as boost::optional or pointers)? Are there better ways of doing this? At this point I'm quite happy with the current setup but I was hoping to get some fresh ideas or productive criticism of the current implementation.

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• Can't change folder background

  - by newcomer

  I tried to change via dragging from the Backgrounds and Emblems window, but the icon just goes back to that window rather than changing the folder background.However, I can change the task bar by this drag-n-drop. Probably it is something about changing ownership permission? if so how to change that? In /home/mashruf/.gconf/apps/nautilus/preferences/%gconf.xml file it says:, Should I change this file? how? <?xml version="1.0"?> <gconf> <entry name="click_policy" mtime="1297597800" type="string"> <stringvalue>single</stringvalue> </entry> <entry name="default_folder_viewer" mtime="1297597336" type="string"> <stringvalue>list_view</stringvalue> </entry> <entry name="media_autorun_x_content_open_folder" mtime="1297534321" type="list" ltype="string"> </entry> <entry name="media_autorun_x_content_ignore" mtime="1297534321" type="list" ltype="string"> </entry> <entry name="media_autorun_x_content_start_app" mtime="1297534321" type="list" ltype="string"> <li type="string"> <stringvalue>x-content/software</stringvalue> </li> </entry> <entry name="start_with_location_bar" mtime="1297300028" type="bool" value="true"/> <entry name="side_pane_view" mtime="1297269334" type="string"> <stringvalue>NautilusTreeSidebar</stringvalue> </entry> <entry name="navigation_window_saved_maximized" mtime="1297600306" type="bool" value="false"/> <entry name="navigation_window_saved_geometry" mtime="1297600306" type="string"> <stringvalue>964x608+59+2</stringvalue> </entry> <entry name="sidebar_width" mtime="1297390418" type="int" value="192"/> </gconf>

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• links for 2011-02-02

  - by Bob Rhubart

  Oracle WebLogic's YouTube Channel Tired of reading? Watch and learn.  (tags: oracle weblogic youtube) Chris Muir: JDev: ADF BC and ADF Libraries: The Library Private property Oracle ACE Director Chris Muir illustrates the use of ADF Libraries. (tags: oracle otn oracleace) Satyajith Nair: Starting a SOA Project? Don't forget the Service Registry!! Satyajith Nair argues that "even with small projects, adding a Service Registry in the architecture has significant benefits with regards to Developer Productivity, Build Quality, Ease of maintenance and Architecture Flexibility." (tags: oracle infosys soa serviceregistry soagovernance) Matthias Wessendorf: Weblog Apache MyFaces in the cloud - Part II Matthias Wessendorf says: "A few days ago I did a quick test to see how well Apache MyFaces works in the cloud. The Amazon Beanstalk test was a success." (tags: oracle apache cloud) SOA & E2.0 Partner Community Forum - registration is open! (SOA Partner Community Blog) Jurgen Kress with an update on next month's event in the Netherlands. (tags: oracle otn soa enterprise2.0) Well Hello There, WebCenter PS3 VM | The AppsLab Jake Kuramoto says: "You may recall my struggle last year to assemble and document a WebCenter VM. Well, apparently other people thought it was a good idea..." (tags: oracle otn enterprise2.0 webcenter) InfoQ: Proving the Business Value of SOA Anne Thomas Manes discusses SOA goals and objectives used to measure a system’s success, measuring the business value, SOA project metrics, and recommendations on proving the business value of SOA. (tags: ping.fm) InfoQ: Amazon Will Offer Oracle Database 11g on RDS Amazon will offer Oracle Database 11g on RDS which brings patching, backup, replication, and failover support to Oracle’s database. (tags: ping.fm)

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